Backpack



FIG. 1 is a front top-right isometric view of a backpack showing the design.

FIG. 2 is a front elevation view thereof.

FIG. 3 is a bottom plan view thereof.

FIG. 4 is a front bottom-left isometric view thereof; and,

FIG. 5 is a fragmentary front elevation view thereof taken along the line 3-3 in FIG. 3.

The dashed lines shown in the drawings illustrate portions of the backpack that form no part of the claimed design. The shading lines shown in the drawings represent the three-dimensional contour of the claimed design and are not intended to indicate surface decoration. 

CLAIM The ornamental design for a backpack, as shown and described. 